Ten cases of Hodgkin's disease was massive bone marrow invasion. This particular form of the disease is seen either at the outset or in Stage IIIB with a rapid course. It is reflected by a pancytopaenia with poor marrow with little or no superficial nodes. These very atypical forms of Hodgkin's disease must thus always be considered as a possibility in the context of acute malignant myelofibrosis. They indicate a special and unexplained behaviour of the host to the Hodgkin's tumour.